When you don't know what a pregnant woman is, you don't realize how many pregnant women there are around you. When you understand the concept, you often see pregnant women. The world changes because of an individual's perception, not because there are more pregnant women, but because the perception has changed.
Psychologists can always discover people with various psychological issues around them, which is based on the same principle.
Xiao Qian looked at the people under the overpass, wondering how many of them had severe mental illnesses like Zheng Xu?
Very few.
But how many of them needed psychological counseling or were emotionally distressed?
A lot.
Everyone will have their sad moments and brief emotional distress, but many problems can be resolved over time.
